Double windowpane construction



* Sept. 19, 1939.A

`L. W. SHUTTS DOUBLE wINDowPANE CoNsTRUcrrmil` Filed March 25, 1936 3Sheets-Sheet l SPt- 19, 1939. L. w. sHuTTs f 2`,173,664

DOUBLE wmDowPANE CONSTRUCTION Filed March 2:5, 1936 s sheets-sheet 2 lDOUBLE WINDOWPANE CONSTRUCTION Filed March 23, 193s s vsheets-smet sPatented Sept. 19, 1939 UNITED STATES PATENT OFFICE 2,173,664 DOUBLEwmnowrANE CONSTRUCTION Leroy W. Shutts, Detroit, Mich., assignor toGeneral Motors Corporation, Detroit, Mich., a corporation of DelawareApplication March 23, 1936, Serial No. 70,182

2 Claims.

tion on the window when there is a diiferent temperature on either sidethereof and a high relative humidity on the warmer side.

It has long been appreciated that the use of an 10. insulating air spacebetween two panes would retain the temperatures of the respective panesmore nearly at the temperatures on the inside and outside of the window,and attempts havebeen made to secure this in many different ways,

for particular purposes.

The development of air conditioning for rooms and the maintenance ofideal indoor atmospheric conditions irrespective of the outsideconditions has increased the demand'for a satisfactory double glazedwindow of simple construction.

The eicacy of the air insulation depends on the extent to which thespace between the panes is sealed from the inside and outsideatmospheres. In any design in which the panes cannot be readilyseparated for cleaning the adjacent sides of the panes, the insulatingair space should be completely and permanently sealed to preventthebreathing which occurs with expansion and contraction due to temperaturechanges, and the consequent collection of moisture and dust within theseparating space, which occurs if there is any leakage, however slight.Such collection of moisture and dust may not be in evidence until aftera considerable number of temperature variations when it mayA appear as amore or less'permanent condensation, particularly on the inner surfaceof the outer pane.

Heretofore the foregoing requirements for maintaining eifective airinsulation with the n panes either readily separable or permanentlysealed, have been but indifferently met.

The object of the present invention is a double window pane of practicalconstruction in which the air space between the panes is completely anda permanently sealed.

A further object of the invention is a double Window pane unit adaptedfor factory production in standard sizes, but which isI capable ofconstruction in any desired size, on any given site,

f with but little necessary apparatus.

The above and other objects of the invention will be apparent as thedescription proceeds.

According to the invention the panes of glass, 0r other transparentmaterial are mounted and (Cl.A 20-56.5)

suitable channeled section strip material. The strip material has a pairof channels for the panes spaced by an intervening separating ridge, the.outer edges of the channels embracing the outside edges of the paneswhich are held and hermetically sealed in the frame so provided by asuitable thermoplastic sealing compound.

The drawings show the various parts of a double glass window pane unit,and the manner in which it is assembled,

In the drawings- Figure 1 shows a completed double glass win- Figure 6shows a perspective View of the cornponent parts of the double glasswindow pane unit all assembled in proper relationship with the exceptionof one crner piece ofthe frame.

Figure 7 shows a spring loaded jig in which the assembly is placedbefore being heated to the free flowing temperature of the sealingcompound at which the spring load is capable of squeezingthe parts ofthe assembly together into their final closed position.

Figure 8 shows the double glass window pane assembly in position in thejig, with springs exerting an equilibrated pressure on all sides there-Referring now to Figures 1 to 6, the panes of glass i and 2 are heldinseparated relationship in frames of a suitable material such as copperand consisting of side members 3 and 4, end members 5 and 6 and cornerpieces 1', 8, 9 and I0. The side and end members are cut with miteredends from suitable strip copper rolled to the section shown most clearlyin Figures 2 and 3. The channel grooves are suiciently wide to provide afree t, of capillary dimensions between the channel and glass.

Air insulating space of any desired thickness may be provided by makingthe strip with a separating portion of the requisite width between thetwo channels. A separation as small as M3" has been found sufficient forall normal requirements A vent hole is provided in one of the members lsealed in spaced -relation in frames built from 31. 4,. 5 or 6 forreasons later to be given. In the f drawings this vent hole is shown atIl in the member 3 in Figure 3.

Bitumen has been found a satisfactory sealing compound. `By extrusioninto cold water the bitumen may be formed into a string at roomtemperature in which form it can be very conveniently used.

In assembling, ythe panes and the metal strips being cut to proper size,a string I2 of bitumen I2 is placed in each channel groove of thestrips. The two panes of glass are placed in the grooves of one sidestrip as shown in AFigure 5 and the opposite strip is placed on top ofthe panes. The ends of the glass panes are then, in turn, set into theend strips and a small piece of bitumen is placed over the cornerswithin the external groove of the strips and the corner pieces are thenpushed on.

The assembly with all its component parts separated by the bitumenstring, as shown in Figure 6, is then placed in the self-aligning jigshown in Figure 7. This consists of a pair of end members I3 and I4 anda floating pair of side members I5 and I6. Pivotally attached to theends of each member I3 and I4 are bell crank levers I'I and I8 eachhaving rollers I9, capable of bearing against the side members I5 andI6. The bell crank levers are so arranged that forces applied, betweenthe bell crank levers at those ends of the end members opposite to eachother, in a direction to draw the end members together, will, throughthe rollers I9, tend to thrust the side members together. The requiredforces are provided by coil springs which are hooked over the bell cranklevers I8 and which through turnbuckles 2I are connected through shortpivotal links 22, to the bell crank levers I`I of each end member. v

Figure 8 shows the double glass window pane assembly in position in thejig with the springs exerting a pressure tending to squeeze all theparts together into their proper position.

The entire assembly including the jig is next placed in an oven andheated to an even temperature sufficient to melt the bitumen sealingcompound so that it will freely flow, but not high enough to Volatilizethe bitumen or to drive 01T any vapors or smoke therefrom. When such atemperature is maintained for a sufcient period of time the bitumenflows between theglass and the channels in the frame and at the sametime the window pane assembly is squeezed together by the springpressure of the jig. The bitumen only fiows and makes a seal and asuflicient bond between the parts, at the places between which there iscapillary attraction, and the clearance between the glass and the sidesof the channels of the strip must be such as to provide this.

Probably for the reason that due to its expansion, the pressure of theair between the panes is a little higher than the outside pressure, thebitumen does not flow over the inside of the glass panes, although anyexcess bitumen will flow over the outside of the glass at the edges ofthe frame.

Theventholeprevlouslymentionedlsprovidedln order to provide adenitepathfortheegress of air from between the panes as it expands inthe oven andtopermitareturnowof airbetween the panes as the assembly isreturned to room temperature. Without such a vent hole it is found thatthe air will find its own path of flow out of and into the space betweenthe panes at an indeterminate point, and since the inflow of air takesplace therethrough as the asphalt is cooling and solidifying to a pointat which it is incapable of flowing, it is not able automatically toseal itself, nor can the place Where sealing is required, be readilyfound even if it were capable of being sealed by other means. The venthole provides .a determinate path which can be sealed with bitumen orany other suitable cement when the assembly has cooled to roomtemperature and there is ordinary atmospheric pressure between thepanes.

When the double glass window pane has cooled to room temperature, it isremoved from the jig, the vent hole is sealed and the excess sealingcompound is scraped off the outside of the glass panes.

The double glass window pane can then be tested for leaks by immersingit in warm water, which heats the air in the space between the panescausing bubbles to form at any minute opening or crack.

The double glass window pane is then a complete unit with all its jointshermetically sealed and with the advantage of protection to the edges ofthe glass, having the appearance shown in Figure 1, and capable ofcomparatively rough handling without being broken or spoiled.Furthermore, since the panes are cut somewhat smaller than the insidedimensions of the frame in its final condition of assembly, the glass isnot at any time subjected to any considerable pressure during any partof the fabrication of the double glass window pane and the possibilitiesof breakage in manufacture are thereby reduced.

I claim:

1. A double window pane structure having a frame of strip material forits edges, said strip material being formed with two channels spacedfrom each other by a separating ridge and pro- Viding a clearance spaceof capillary dimensions between the sides of each channel and the sidesof the pane which is inserted therein, and a thermoplastic sealingcompound in the channels, to fill the clearance spaces by capillaryattraction and bond and sealV the parts together.

2. The combination according to claim 1 in which corner strengtheningand clamping pieces are provided for the outside corners of the frame,said corner pieces being of general L-shaped form to embrace thecorners, being press-fitted within the groove formed by the separatingridge of the frame, and being bonded thereto by a thermoplastic sealingcompound in said groove.

LEROY W. SHUTTS.

